Presence of different mitogenic activities in the nocturnal peritoneal effluent of patients treated with CAPD.

Peritoneal cells in continuous ambulatory peritoneal dialysis (CAPD) patients are continually being regenerated. We previously reported that nocturnal peritoneal effluent is mitogenic on human and mouse fibroblasts in culture, especially when a comitogen is present. The nature, origin, and role of this mitogenic activity remain undetermined. The data resulting from the addition of different comitogen to dialysate suggest that the peritoneal effluent contains different growth factors with molecular weight greater than 10,000 dalton. Also, the presence of a growth inhibitor is plausible. In conclusion, different growth-promoting and inhibiting activities are present in the peritoneal effluent, suggesting a complex cellular relationship as a result of peritoneal dialysis with unknown consequences.